Brooks is out for the season after hurting his posterior cruciate ligament and possibly his medial collateral ligament while covering a kickoff.
"Terrence Brooks doesn't look good," head coach John Harbaugh said. "He'll be out for the year."
Jackson's status for the remainder of the season hasn't been determined. He injured his posterior cruciate ligament, according to a source.
"I don't have a final word on Asa," Harbaugh said.
Jackson was replaced by former Miami Dolphins cornerback Rashaan Melvin, who played well in his first NFL game with five tackles, one for a loss and a pass deflection. He effectively shadowed Jaguars wide receivers despite a lack of experience.
"Melvin came in there and did a great job and played really well and was excited to get out and get a chance," Harbaugh said. "The next guy has to step up, and they will. This is a team sport, and our guys have done a good job with that so far, and they'll keep doing it."